ANALYSTS OF NONEQUILIBRIUM SOLIDIFICATION OF SUBEUTECTIC SILLUMINES USING MULTICOMPONENT PHASE-DIAGRAMS

A method has been proposed for analyzing the formation of cast structu re in ternary and quaternary sillumines during nonequilibrium solidifi cation. The method uses the equilibrium phase diagrams in the assumpti on that the peritectic reactions are suppressed and the eutectic react ions occur in accordance with the phase diagram. A possible mechanism whereby cooling rate affects the sequence of phase solidification has been suggested. The Al-Si-Fe, Al-Si-Cu-Mg, and Al-Si-Mg-Fe systems hav e been analyzed as examples. The method enables investigation of the r eal phase composition of cast sillumines.